Myopathies decrease muscle functionality. Mutations in ryanodine receptor 1 (RyR1) are often associated with myopathies with microscopic core-like structures in the muscle fiber. In this study, we identify a mouse RyR1 model in which heterozygous animals display clinical and pathological hallmarks of myopathy with core-like structures. The RyR1 mutation decreases sensitivity to activated calciu...

Polymyositis (PM) and dermatomyositis (DM) are inflammatory muscular diseases of unknown cause. An immune mechanism may cause these inflammatory myopathies.'2 The mainstay of therapy in inflammatory myopathies is corticosteroids.3 In patients who are resistant to corticosteroids, many therapies are available: immunosuppressive drugs, plasmapheresis, or total body irradiation.4 These therapies a...

Muscle symptoms and signs are a frequent reason for general neurological consultations. Weakness is the most reliable clinical indicator of myopathy. Fatigue and exercise intolerance and myalgias frequently occur in non-myopathic conditions. Cramps and myoglobinuria are more often due to systemic factors than being a sign of a metabolic or other myopathy. Contractures and myotonia are rare find...

It is not known whether eosinophilic myositis is a specific histopathological feature of limb girdle muscular dystrophy 2A (LGMD2A). Number and location of eosinophils in skeletal muscle biopsies (n=100) was analysed by Giemsa and modified hematoxylin/eosin staining in patients with genetically confirmed myopathies (LGMD2A, LGMD2B, LGMD2L, facioscapulohumeral muscular dystrophy, dystrophinopath...

Polymyositis is one of the inflammatory myopathies. It a chronic autoimmune disease that usually involves proximal muscles. caused by an infiltrate skeletal muscle. Notably, dysphagia occurs in one-third patients. Traditional treatment with steroids and immune modulators has been reported to have varied outcomes recurrent symptomatic flares. The which such myopathies may be severe symptoms myop...